It was a bomb in our high school

The news has released that it was an "incendiary device" at the high school. I am assuming that they were all 3 bombs in the school, post office and power company, but only the school officials have spoken about what they were told so far.
Why bomb the school? I don't understand.

Our town is even on CNN now. I hope the bomber is happy with the publicity. I am ticked.